Range Of Parameters Research Articles

TWO-PHASE FLOW METERING OF MALDISTRIBUTION INSIDE A HEADER BY MEANS OF VENTURI FLOWMETER SOLELY

In evaporators, the distribution of the liquid and vapor phases among the channels is a convoluted problem, depending on a wide range of parameters. However, maldistribution causes important losses of performance. Due to their complexity, the accurate modeling of such two-phase flows is difficult to handle. Hence, experimental studies are still of great importance to help the understanding of maldistribution behaviors inside evaporators. Most of the experimental investigations of two-phase flow distribution are measuring the liquid and vapor quantities in the channels through a phase separation process, increasing the test duration and complexity. As a consequence, the number of parameters investigated is usually limited. Therefore, a new inline instrumentation method would allow for a more complete study by simplifying the measurement process. In the present work, an isothermal air/water mixture was used as fluid. The distribution of the two phases in eight channels of 10-mm I.D. connected to a simplified header was investigated. The inlet mass flow rates considered ranged from 0 to 0.025 kg/s for the water, and from 0 to 0.022 kg/s for the air. Consequently, qualities x up to 0.7 and void fractions α up to 0.9 were reached. All the tests were carried at a pressure condition of 7 bar to reach a liquid to vapor density ratio similar to what is encountered for traditional refrigerant. Finally, to allow a continuous measurement process, the mass flow rates in each of the 10-mm I.D. channel were measured using a flowmeter calibrated on a separate line. Since no void fraction meter was coupled, a new iterative methodology, based on the Venturi pressure drops measurement solely, was developed and is proposed here. It proved to successfully predict the vapor and liquid phase flow rates in each channel.

Exploring the Circumstellar Environment of Tycho’s Supernova Remnant. I. The Hydrodynamic Evolution of the Shock

Among Type Ia supernova remnants (SNRs), Tycho’s SNR has been considered as a typical object from the viewpoints of its spectroscopic, morphological, and environmental properties. A recent reanalysis of Chandra data showed that its forward shock is experiencing a substantial deceleration since around 2007, which suggests recent shock interactions with a dense medium as a consequence of a cavity-wall environment inside a molecular cloud. Such a nonuniform environment can be linked back to the nature and activities of its progenitor. In this study, we perform hydrodynamic simulations to characterize Tycho’s cavity-wall environment using the latest multiepoch proper motion measurements of the forward shock. A range of parameters for the environment is explored in the hydrodynamic models to fit with the observational data for each azimuthal region. Our results show that a wind-like cavity with ρ(r) ∝ r −2 reconciles with the latest data better than a uniform medium with a constant density. In addition, our best-fit model favors an anisotropic wind with an azimuthally varying wind parameter. The overall result indicates a mass-loss rate which is unusually high for the conventional single-degenerate explosion scenario.

Scalable stellar evolution forecasting

Many astrophysical applications require efficient yet reliable forecasts of stellar evolution tracks. One example is population synthesis, which generates forward predictions of models for comparison with observations. The majority of state-of-the-art rapid population synthesis methods are based on analytic fitting formulae to stellar evolution tracks that are computationally cheap to sample statistically over a continuous parameter range. The computational costs of running detailed stellar evolution codes, such as MESA, over wide and densely sampled parameter grids are prohibitive, while stellar-age based interpolation in-between sparsely sampled grid points leads to intolerably large systematic prediction errors. In this work, we provide two solutions for automated interpolation methods that offer satisfactory trade-off points between cost-efficiency and accuracy. We construct a timescale-adapted evolutionary coordinate and use it in a two-step interpolation scheme that traces the evolution of stars from zero age main sequence all the way to the end of core helium burning while covering a mass range from 0.65 to 300 M⊙. The feedforward neural network regression model (first solution) that we train to predict stellar surface variables can make millions of predictions, sufficiently accurate over the entire parameter space, within tens of seconds on a 4-core CPU. The hierarchical nearest-neighbor interpolation algorithm (second solution) that we hard-code to the same end achieves even higher predictive accuracy, the same algorithm remains applicable to all stellar variables evolved over time, but it is two orders of magnitude slower. Our methodological framework is demonstrated to work on the MESA ISOCHRONES AND STELLAR TRACKS (Choi et al. 2016) data set, but is independent of the input stellar catalog. Finally, we discuss the prospective applications of these methods and provide guidelines for generalizing them to higher dimensional parameter spaces.

Parameter Regimes of Hemispherical Dynamo Waves in a Spherical Shell From 3D MHD Simulations

AbstractThe MHD dynamo process, which generates a magnetic field through turbulent motion inside an electrically conducting fluid layer, is of fundamental importance to earth and planetary science. Numerical simulations have been employed to investigate the MHD dynamo process for several decades and can reproduce various observed magnetic field properties, including dipolar and multipolar magnetic fields with different field strengths. In this work, we focus on a particular type of dynamo solution where the magnetic fields are concentrated in either the northern or the southern hemisphere and show wave‐like regular reversals and propagations. We surveyed an extensive parameter range and found that these dynamo waves are the predominant solution when the thermal drive is sufficient to maintain a magnetic field but insufficient to drive a chaotic multipolar dynamo. These waves seem to require moderate convection forcing, characterized by a local Rossby number between 0.04 and 0.1. Further investigation shows that the waves likely are αΩ Parker dynamo waves, based on the consistency of the simulated wave frequency with the mean‐field dynamo theory. Our results have implications for the observed dichotomy of planetary magnetic fields as well as the possibility of the absence of paleomagnetic records while the dynamos were still operating.

Hot processing map and high temperature deformation behaviour of TB17 Ti alloy

The thermal compression experiments of TB17 titanium alloy under different thermal deformation process parameters were carried out using a thermal simulation compressor. The high-temperature plastic flow behaviour of the alloy was studied. It was found that with the decrease of the deforming temperature and the increase of the strain rate, the flow stress increased, and the discontinuous yield phenomenon occurred in hot deformation. The larger the strain rate, the more obvious the discontinuous yield phenomenon. The thermal activation energy Q decreased with the increase of strain, and the average value of activation energy Q is 209.54 KJ / mol. The constitutive equation of high-temperature plastic flow of TB17 titanium alloy was established. The predicted values of this equation are in good agreement with the experimental values. The average error is 3.987 %, and the correlation coefficient is 0.9972, which has high accuracy. Based on the Prasad criterion, the hot processing map of TB17 titanium alloy was constructed. It was found that the flow instability zone was mainly concentrated in the high strain rate region. The flow instability zone was determined to be 795 °C ~ 895 °C, 0.046s-1 ~ 1s-1, and the stable deformation zone was mainly located in the region with high temperature and low strain rate. The optimum processing parameter range is 860 °C ~ 895 °C, 0.001 s-1 ~ 0.025 s-1.

Various solitons induced by relative phase in the nonlinear Schrödinger Maxwell-Bloch system.

We study the effect of relative phase on the characteristics of rogue waves and solitons described by rational solutions in the nonlinear Schrödinger Maxwell-Bloch system. We derived the rational rogue wave and soliton solutions with adjustable relative phase and present the parameter range of different types of rogue waves and solitons. Our findings show that the relative phase can alter the distribution of rational solitons and even change the type of rational solitons, leading to a rich array of rational soliton types by adjusting the relative phase. However, the relative phase does not affect the structure of the rogue wave, because the relative phase of the rogue wave changes during evolution. In particular, we confirm that the rational solitons with varying relative phases and the rogue waves at corresponding different evolution positions share the same distribution mode. This relationship holds true for rogue waves or breathers and their stable counterparts solitons or periodic waves in different nonlinear systems. The implications of our study are significant for exploring fundamental excitation elements in nonlinear systems.

Universal Casimir attraction between filaments at the cell scale

The electromagnetic Casimir interaction between dielectric objects immersed in salted water includes a universal contribution that is not screened by the solvent and therefore long-ranged. Here, we study the geometry of two parallel dielectric cylinders. We derive the Casimir free energy by using the scattering method. We show that its magnitude largely exceeds the thermal energy scale for a large parameter range. This includes length scales relevant for actin filaments and microtubules in cells. We show that the Casimir free energy is a universal function of the geometry, independent of the dielectric response functions of the cylinders, at all distances of biological interest. While multiple interactions exist between filaments in cells, this universal attractive interaction should have an important role in the cohesion of bundles of parallel filaments.

Impact of periodic vaccination in SEIRS seasonal model.

We study three different strategies of vaccination in an SEIRS (Susceptible-Exposed-Infected-Recovered-Susceptible) seasonal forced model, which are (i) continuous vaccination; (ii) periodic short-time localized vaccination, and (iii) periodic pulsed width campaign. Considering the first strategy, we obtain an expression for the basic reproduction number and infer a minimum vaccination rate necessary to ensure the stability of the disease-free equilibrium (DFE) solution. In the second strategy, short duration pulses are added to a constant baseline vaccination rate. The pulse is applied according to the seasonal forcing phases. The best outcome is obtained by locating intensive immunization at inflection of the transmissivity curve. Therefore, a vaccination rate of 44.4% of susceptible individuals is enough to ensure DFE. For the third vaccination proposal, additionally to the amplitude, the pulses have a prolonged time width. We obtain a non-linear relationship between vaccination rates and the duration of the campaign. Our simulations show that the baseline rates, as well as the pulse duration, can substantially improve the vaccination campaign effectiveness. These findings are in agreement with our analytical expression. We show a relationship between the vaccination parameters and the accumulated number of infected individuals, over the years, and show the relevance of the immunization campaign annual reaching for controlling the infection spreading. Regarding the dynamical behavior of the model, our simulations show that chaotic and periodic solutions as well as bi-stable regions depend on the vaccination parameters range.

Shooting Simulator «Inhibitor»: Mathematical Support of the Shooting Range Special Effects

The article describes mathematical tools and algorithms for preparing for a shooting exercise with selection of a combat scenario and setting the parameters of the shooting range (special effects) for the optical-electronic shooting simulator 'Inhibitor' developed at Institute of mechanics UdmFRC UB RAS and at Computer facilities department of Kalashnikov ISTU jointly with JSC 'Kalashnikov' Concern'. The tactical and technical task for displaying various types of shooting ranges (steppe, wooded, mountain and urban) is given, taking into account the season (summer/autumn/winter/spring) and time of the day (morning/day/evening/night) with possible illumination of the area at night and support for the 'atmospheric effect' by reducing contrast and possibly of fog with precipitation (rain/snow). As a result of the work done, all the problems are solved using the gamma function and other image transformations outside the main cycle of animation of the target environment. When choosing a shooting exercise scenario, one can combine two features for different types of weapons and execute them simultaneously at different workplaces, one can view and edit the script and configure parameters (for example, disable the random location of targets or group them at short range, change the order of display, allow special combat effects and active behavior of targets, set air temperature and pressure and wind speed, etc.). A gamma function study was carried out to change the time of day of the shooting range image and models of the application of fog (translucency) and precipitation (ripples images). The literature review confirms the promise of further research and development of electronic rifle simulators through the improvement of computing tools and the development of software libraries with the aim of improving the accuracy of simulating a shooting range and flexible adjustment of both atmospheric and combat parameters of training exercises. It is necessary to constantly expand the possibilities of realism of the target situation and reduce the cost, which means to increase the competitiveness of electronic shooting simulators.

Responce Surface of Drying Parameters on Some Physical Properties Related to Floatability of Extruded Fish Feeds

Fish feeds drying plays a major role in the aquaculture industry by ensuring preservation and quality of feed for effective growth and development of farmed fish. Optimization the drying parameters such as drying temperature, drying air velocity and relative humidity plays a crucial role in achieving Response Surface Methodology is a useful to optimized variables/factors more practically as compared to just the statistically significant test for a particular point. The aim of this research to optimize the drying process of an extruded fish feeds which affect the floatability of the feeds. 2000 g of the extruded feeds was dried in a continuous flow belt dryer. The experiments were performed at air temperature of 60, 70, 80, 90 and 100°C, air velocities of 0.7, 0.8, 0.9, 1.0 and 1.2 m s-1 and drying belt linear speeds of 50, 55, 60, 65 and 70 rpm. The dried extruded fish feed was subjected to extensive physical properties which are: unit density (kg m-3), water stability (%), sinking velocity and relative absorption ratio. The surface response of each of this physical property of the dried extrudates’ were determined. The result shows that the operational parameter can optimally explain about 90.45%, 93.72%, 95.98% and 70.77% change in the density, water stability, sinking velocity and the relative absorption ratio respectively of the extrudate via quadratic function. The optimum predicted values for air temperature of 97.49°C, conveyor belt speed of 50 rpm and air velocity of 1.10 m s-1 were obtained for the dryer within the range of the input parameters.

Показатели суточного мониторинга артериального давления у лиц старческого возраста c хронической сердечной недостаточностью в зависимости от жесткости сосудов

INTRODUCTION: Measurement of arterial pressure (AP) is a standard method for assessing the risk of developing cardiovascular diseases. Analysis of systolic and diastolic pressure, as well as their ratio, can help determine the risk of developing cardiovascular diseases. One of the ways to diagnose elevatedarterial pressure is daily monitoring of arterial pressure (DMAP). An increase in AP in the elderly is usually associated with an increase in the stiffness of the vascular walls. This leads to an increase in systolic arterial pressure (SAP) and pulse pressure (PP), as well as a decrease in diastolic arterial pressure (DAP). Elevated arterial pressure enhances the load on the heart and can lead to its pathological alterations. A decrease in DAP impairs the blood supply to the heart, which can cause ischemia and fibrosis; the result isdevelopment of diastolic dysfunction, which is the main cause of chronic heart failure (CHF). Currently, a promising way to determine the arterial stiffness is measurement of a cardio-ankle vascular index.The prognostic and diagnostic value of this parameter has been confirmed by numerous studies. It is important to study the parameters of the daily AP profile and arterial stiffness in older patients with CHF. This permits to identify malignant forms of elevated blood pressure, which can lead to cardiovascular complications. AIM: To study the characteristics of the parameters of the daily arterial pressure profile in elderly patients with CHF, depending on the vascular stiffness determined by volume sphygmography. MATERIALS AND METHODS: One hundred and twenty elderly patients with CHF undergoing treatment in a cardiology hospital were examined. By the method of volume sphygmography, the patients were divided into groups with ‘vessels of normal stiffness’ (group 1) and ‘stiff vessels’ (group 2), with subsequentDMAP. A statistical analysis of the parameters of the daily AP profile in the groups was performed. RESULTS: In patients of group 1, both daytime and nighttime SAP, DAP and PP, were significantly higher than in patients of group 2. Besides, in group 1, there was a nighttime decrease in SAP and DAP, while the morning rise of SAP was statistically higher in group 2, and no differences were recorded between the groups in the morning rise of DAP. When assessing the ankle-brachial index in patients of group 2, daytime and nighttime SAP and DAP were statistically higher. In group 1 (with probable peripheral atherosclerosis), PP was higher both during the day and at night. The nocturnal decrease in SAP was statistically higher in group 2, while the nocturnal decrease in DAP prevailed in group 1. The morning rise of SAP and DAP was higher in group 1. CONCLUSION: The DMAP data may indicate to some extent the severity of hypertension in patients with CHF, and this probably depends on the ‘stiffness of the vessels’. In elderly patients with CHF with ‘normal stiffness’ of vessels, the parameters of the daily arterial pressure profile were higher than in patients with ‘stiff vessels’. However, the daily range of parameters of the daily arterial pressure profile was greater in the group of patients with ‘stiff vessels’ (group 2).

Optimizing Transportation Safety with Realtime Air Quality Monitoring and Health Alert System

Abstract: The proposed system is a smart air quality monitoring and health alert system designed specifically for truck drivers. The system aims to address the issue of poor air quality within truck cabins, which can lead to a range of health problems for drivers who spend extended periods on the road. The system utilizes advanced sensors to monitor the air quality within the truck cabin, measuring a range of parameters including carbon monoxide, carbon dioxide, and particulate matter. In addition to air quality monitoring, it also includes a health alert system that can notify drivers of potential health risks based on their personal health data and environmental conditions. This feature helps drivers take proactive measures to prevent health problems and maintain their well-being while on the road. Proposed system is a cost-effective and user-friendly solution that can improve the health and safety of truck drivers, ultimately benefiting both the drivers and the trucking industry. It can also be easily integrated into existing fleet management systems, making it a scalable solution for trucking companies of all sizes.

An Investigation of the Impact of Amenities on Condominium Apartment Prices in Colombo, Sri Lanka with Machine Learning

Condominium prices of a location are heavily impacted by the availability of neighbourhood amenities, which attract people to that location. Studies that employ machine learning to evaluate the impacts of amenities on condominium prices are a few, despite indications of increased accuracy. Hedonic models are used in the majority of current studies on housing pricing. Yet, the application of machine learning will improve accuracy and be more effective for the identification of multi-collinearity and non-linear relationships between property prices and the availability of amenities for a wide range of parameters. The aim of this study is to investigate the possible relationship between urban amenities surrounding condominium apartments and their market prices. The study uses data from the Google Maps Platform to examine the link between neighbourhood amenities and the prices of 236 condominiums in Colombo, Sri Lanka. 56 significant amenity characteristics were found using the eXtreme gradient boosting (XGB) algorithm, and the variety of correlations between amenities and condominium prices as restricted positive, accelerated positive, crooked, humped, and negative was explained. Results demonstrated that while a beautiful urban environment requires a variety of facilities, the popularity and other attributes of amenities affect condominium prices in numerous non-linear ways. Therefore, public and private organizations must work together to create integrative strategies that enhance and maintain the variety and accessibility of urban amenities.

基于离散元模拟的白米仿真参数标定

Aiming at the lack of discrete element simulation models and parameters for rice polishing, grading, color sorting and other technologies and equipment, and the difficulty of guiding equipment design and optimization through simulation, this paper calibrates the simulation parameters of white rice based on angle of repose (AOR) test and simulation methods. Huanghuazhan and Dongnong 429 white rice were selected as research object. Numerical model of white rice was established by multi-sphere filling. According to physical test and references, the simulation parameter range of white rice particles was determined. Plackett-Burman test was used to screen parameters, and it was found that the particle-particle static friction coefficient and particle-particle rolling friction coefficient had significant effects on the AOR of white rice. The regression model between the AOR and the significance parameter was established according to the central composite design method. The simulation parameter combination that has significant influence on the physical AOR was determined through the optimization design, and verified by the simulation test. The simulation AOR was compared with the physical AOR, and the relative error of the two kinds of white rice was less than 3%. The results show that the calibration method proposed in this study can accurately simulate the physical AOR test, which can provide reference for discrete element simulation of white rice processing.

Gait alterations in patients with adult spinal deformity

Adult spinal deformity patients (ASD) experience altered spinal alignment affecting spatiotemporal parameters and joint kinematics. Differences in spinal deformity between patients with symptomatic idiopathic scoliosis (ID-ASD) and patients with "de novo" scoliosis (DN-ASD) may affect gait characteristics differently. This study aims to compare gait characteristics between ID-ASD, DN-ASD, and asymptomatic healthy matched controls. In this observational case-control study, ID-ASD (n=24) and DN-ASD (n=26) patients visiting the out-patient spine clinic and scheduled for long-segment spinal fusion were included. Patients were matched, based on age, gender, leg length and BMI, with asymptomatic healthy controls. Gait was measured at comfortable walking speed on an instrumented treadmill with 3D motion capture system. Trunk, pelvic and lower extremities range of motion (ROM) and spatiotemporal parameters (SPT) are presented as median (first and thirds quartile). Independent t-test or Mann-Whitney U test was used to compare ID-ASD, DN-ASD and controls. Statistical Parametric Mapping (independent t-test) was used to compare 3D joint kinematics. DN-ASD patients walk with increased anterior trunk tilt during the whole gait cycle compared with ID-ASD patients and controls. ID-ASD walk with decreased trunk lateroflexion compared with DN-ASD and controls. DN-ASD showed decreased pelvic obliquity and -rotation, increased knee flexion, and decreased ankle plantar flexion. ID-ASD and DN-ASD displayed decreased trunk, pelvic and lower extremity ROM compared with controls, but increased pelvic tilt ROM. ID-ASD patients walked with comparable SPT to controls, whereas DN-ASD patients walked significantly slower with corresponding changes in SPT and wider steps. DN-ASD patients exhibit distinct alterations in SPT and kinematic gait characteristics compared with ID-ASD and controls. These alterations seem to be predominantly influenced by sagittal spinal malalignment and kinematic findings in ASD patients should not be generalized as such, but always be interpreted with consideration for the nature of the ASD.

Nutrient status of overlying water and sediment of West Lake, Hangzhou, China

A comprehensive investigation of the physicochemical properties of overlying water and sediments in Hangzhou West Lake, China was conducted. A wide range of crucial physical parameters were analyzed, revealing significant spatial and seasonal differences. Total nitrogen (TN), total phosphorus (TP), and chemical oxygen demand (COD) concentrations in overlying water met the Class III limits (TN ≤2 mg/L, TP ≤0.2 mg/L, COD ≤20 mg/L) of the Environmental Quality Standard for Surface Waters (GB3838–2002), indicating relatively good overall water quality. However, concerns were raised regarding potential eutrophication, particularly evident during summer with explosive chlorophyll-a growth in certain lake areas like WH (266 mg/L) and XLH (239 mg/L). Lakes receiving direct diversion showed lower TN and TP versus non-diverted lakes. This research provides valuable insight into the complex nutrient dynamics and conditions of West Lake, improving understanding of lake ecosystem management and sustainable conservation strategies.

Circular steel tube-confined ultra-high performance concrete beam-column: Database, modeling, and design

The fiber beam element (FBE) model is widely used to simulate and predict the nonlinear behavior of structures owing to its simplicity and high computational efficiency. The accuracy of the FBE simulation of ultra-high-performance concrete (UHPC) filled steel tubular (UHPCFST) members is mainly dependent on the input materials and interactions between the steel tubes and concrete, such as second-order effect, yielding of steel tubes and passive confinement effect to the UHPC. This work proposes uniaxial effective stress-strain models of UHPC confined by circular steel tubes based on existing experimental data that are integrated into the FBE model to predict the nonlinear behavior of UHPCFST members. The robustness and reliability of the proposed material models are comprehensively verified against a database encompassing a wide range of materials and geometric parameters under different loading conditions (monotonic and cyclic loading). Furthermore, the application of existing design codes for computing ultimate bending strengths is assessed using an established experimental database. Finally, the ultimate bending strengths of circular UHPCFSTs are calculated using a novel and simplified N–M interaction equation. It is demonstrated that the developed material models could predict the nonlinear behaviors of circular UHPCFST members with good satisfaction, and that current design codes, to some extent, underestimate the ultimate bending strengths of circular UHPCFST columns, the proposed practical method in this study is highly accurate, with a mean value of 1.00.

Angle shear connectors: Pushout tests, numerical simulations and shear strength model

Despite several advantages i.e. ease in fabrication and installation, economic design, higher structural performance etc., the use of angle shear connector has been limited thus far. This is because, there exists no design equation for this connector type in the design standards. Currently, these connectors are designed through the equations originally developed for other connectors. In this study, the performance of angle shear connectors was investigated through experiments and numerical simulations. The experimental results revealed that the connector height influences the performance which is currently ignored in most of the design code equations for channel connectors. The influence of wide range of other parameters was studied through numerical simulations. A parametric study was conducted considering the effect of angle length, height, thickness, welding length, and strength of concrete. Finally, a theoretical model, capable of predicting the strength of angle shear connectors, was developed and verified against experimental results of this study and others from previous literature.

Performance assessment of a system to provide steady high temperature air via solar thermal suspension flow technology with storage and combustion back-up

The imperative for economically viable sources of high-temperature heat without contributing to net carbon emissions has become a pressing global concern, particularly in the context of industrial chemical processes. Solar thermal heat generation emerges as a pivotal solution in addressing this formidable challenge. By concentrating sunlight to achieve high temperatures, solar thermal technology can provide the intense heat required for various industrial applications, including chemical processes, without relying on fossil fuels. This not only helps reduce greenhouse gas emissions but also enhances energy efficiency and sustainability in energy-intensive industries. However, the full integration of solar thermal systems into energy-intensive industrial processes necessitates continued advancements of new technologies to achieve temperatures in the order of 1000 °C. In this paper, the performance of a high temperature concentrating solar thermal plant based on a 50MWth suspension flow solar particle receiver sub-system integrated with sensible thermal storage and combustion backup is analyzed, to supply steady output of reheated air to a downstream thermochemical process. The analysis is performed with transient mathematical models of the receiver and packed bed thermal storage sub-systems considering solar resource variability, written in a Simulink environment, to estimate useful annual thermal gain, thermal efficiency, solar share and levelized cost of solar heat, for a range of parameters including particle mass loading, air mass flow rate, thermal storage capacity and solar multiple. The time-dependent temperature fields of the receiver and thermal losses, together with their influence on the performance of the combined system are reported for each condition with a transient input solar resource spanning over a whole year. New insights are provided of the relative tradeoffs between these parameters on the overall system performance, solar share and levelized cost of solar energy. Also reported is the sensitivity of the levelized cost to different system combinations sized to provide a solar share of up to 75 % of the yearly process thermal demand, along with the influence of the specific costs of the system components varied in the range of ± 60 %.

Numerical study of steel–concrete composite beams strengthened by CFRP plates with prestressed unbonded reinforcement system

This work developed a three-dimension refined finite element (FE) model to study the flexural behavior of steel–concrete composite beams strengthened with CFRP plate by prestressed unbonded reinforcement (PUR) system. The numerical result has excellent agreements with the experimental results on the failure mode, overall load–deflection response and strain development at mid-span section as well as CFRP plates. The verified FE model was applied to carry out a comprehensive parametric study, evaluating the effects of sectional area, prestress level and profile of CFRP plate, to investigate the optimum parameter range of PUR system for beam reinforcement. It is found that the yielding load rises as the sectional area, prestress level, and pillar spacing of CFRP plates increase. Besides, the ultimate bearing capacity of beam can be efficiently improved by increasing the sectional area of CFRP plates, while the mid-span deflection and ductility were maintained at failure. Moreover, as the prestress level of CFFR plate increases, the bearing capacities of reinforced beams marginally rise but the ductility markedly decreases. The ideal prestress level for strengthening is considered as 10 %∼30 %. Furthermore, the profile of CFRP plate has significant impact on failure of reinforced beams, but has little effect on ultimate load. The results of parametric studies are of great significance for the practical reinforcement application of the PUR system with CFRP in bridge engineering.